diff --git a/clock.c b/clock.c
index f987965..3895d09 100644
--- a/clock.c
+++ b/clock.c
@@ -842,16 +842,6 @@ int clock_required_modes(struct clock *c)
 	return required_modes;
 }
 
-/*
- * If we do not have a slave or the rtnl query failed, then use our
- * own interface name as the time stamping interface name.
- */
-static void ensure_ts_label(struct interface *iface)
-{
-	if (iface->ts_label[0] == '\0')
-		strncpy(iface->ts_label, interface_name(iface), MAX_IFNAME_SIZE);
-}
-
 struct clock *clock_create(enum clock_type type, struct config *config,
 			   const char *phc_device)
 {
@@ -961,7 +951,7 @@ struct clock *clock_create(enum clock_type type, struct config *config,
 	required_modes = clock_required_modes(c);
 	STAILQ_FOREACH(iface, &config->interfaces, list) {
 		rtnl_get_ts_device(interface_name(iface), iface->ts_label);
-		ensure_ts_label(iface);
+		interface_ensure_tslabel(iface);
 		interface_get_tsinfo(iface);
 		if (iface->ts_info.valid &&
 		    ((iface->ts_info.so_timestamping & required_modes) != required_modes)) {
diff --git a/nsm.c b/nsm.c
index 269c3c8..e82fc37 100644
--- a/nsm.c
+++ b/nsm.c
@@ -269,9 +269,7 @@ static int nsm_open(struct nsm *nsm, struct config *cfg)
 	STAILQ_FOREACH(iface, &cfg->interfaces, list) {
 		ifname = interface_name(iface);
 		rtnl_get_ts_device(ifname, iface->ts_label);
-		if (iface->ts_label[0] == '\0') {
-			strncpy(iface->ts_label, ifname, MAX_IFNAME_SIZE);
-		}
+		interface_ensure_tslabel(iface);
 		count++;
 	}
 	if (count != 1) {
diff --git a/pmc_common.c b/pmc_common.c
index d5c8b61..6bdaa94 100644
--- a/pmc_common.c
+++ b/pmc_common.c
@@ -351,9 +351,7 @@ struct pmc *pmc_create(struct config *cfg, enum transport_type transport_type,
 	}
 
 	strncpy(iface.name, iface_name, MAX_IFNAME_SIZE);
-	if (iface.ts_label[0] == '\0') {
-		strncpy(iface.ts_label, interface_name(&iface), MAX_IFNAME_SIZE);
-	}
+	interface_ensure_tslabel(&iface);
 
 	if (transport_open(pmc->transport, &iface,
 			   &pmc->fdarray, TS_SOFTWARE)) {